In known ovens, vapors are exhausted via a cooling air duct located above the baking chamber and they are then fed to the outside. Therefore, various embodiments are known in order to make it possible to exhaust vapors via the cooling air duct.
Thus, for example, German publication DE 26 56 565 describes an oven in which the place where the vapor exhaust duct opens up is near the air outlet opening of an exhaust air duct that is configured as a cooling air collector. In order to bring about a suction of the vapors an air baffle is arranged in the cooling air collector so that, in this manner, the cooling air flow, which moves at a relatively high speed, can be admixed with the vapors in the manner of the injector principle.
Another embodiment is described in German publication DE 37 41 975, whereby this is a device for controlling a steam-operated cooking appliance having a cooling air stream that is generated in the pressure duct by a fan. For this purpose, the fan is provided with a return line leading from the pressure duct to the suction side of the fan, and said return line is connected to the cooking chamber via a closable steam outlet opening. Thus, with this embodiment, especially the vapor exhaust can be regulated.
With the known devices, so-called crossflow fans are used for exhausting vapors. They have a poor efficiency, but they are relatively quiet and they fulfill the requirement for a large air volume throughput for purposes of cooling and exhausting vapors. However, due to the structural design, the adaptation to the baking chamber is complex and, as a rule, calls for additional parts. Complex systems as described are generally known. A disadvantage of the models based on the injector principle is that, for example, a constriction has to be created in the exhaust air duct, for example, by means of air baffles, in order to achieve the injector effect.
The other above-mentioned coupling, in which an extended exhaust air connecting piece was placed in a suitable form near the roller of the crossflow fan, has the drawback that the vapors have to be carried via an additional line to the top of the crossflow fan. Here, the concrete realization of the exhaust air connecting piece is very complex, and moreover, water vapor in the connecting piece has to be taken into consideration at temperatures below 100° C.